The present invention is connected to a fiber web machine, such as to paper machines and to tissue-paper machines and to cardboard machines and chemical pulp machines. The present invention, in more detail, relates to the regulating unit for the accomplishing of a linear movement, which is suitable for example for an active attenuation cylinder of the machine bodies and pipe systems of the fiber web machine, such as for example a power cylinder.
At the moment, there are not available such solutions on the market that would serve as a regulating unit, which produces the linear movement fast enough and/or reaches a sufficient power level.
There has been disclosed in a publication EP 819638 a reeling unit, in which the vibration of a press roller is dampened in two different ways. The press roller of the reeling unit, which has been presented in the publication, is a roller, which is pressed against the surface of the fiber web reel, which is under reeling process, and around which the fiber web to be reeled is wound. The press roller is pressed against the surface of the fiber web reel by precisely defined power and the position of the press roller is adjusted by means of load cylinders, which affect to the bearing housings, which loading cylinders can be pneumatic and/or hydraulic cylinders. According to an example, a pressure cylinder is fastened to a bearing housing or a rack is placed next to the bearing housing, which rack comprises a moving mass that has been placed between the load cylinders, in which case the load cylinders and the moving mass form a vibrator, which can be dimensioned to dampen appearing vibrations. According to another example, a pressure cylinder is fastened to the bearing housing, the pressure lines of the pressure cylinder being provided with a throttle means to dampen the movement of the cylinder. This kind of the pressure cylinder can be composed of the load cylinder of the pressing roller, which is throttled by a suitable way. This kind of a known damper solution is suitable for dampening of the vibrations of the roller, which moves actively, but this kind of a known damper solution does not have a direct effect on the vibrations of the machine skeleton or body. Furthermore, it is problematic, because the known damper solution is suitable to be installed only horizontally installed on a fixed base, because otherwise the mass of the known of the cylinder. This kind of the pressure cylinder can be composed of the load cylinder of the pressing roller, which is throttled by a suitable way. This kind of a known damper solution is suitable for dampening of the vibrations of the roller, which moves actively, but this kind of a known damper solution does not have a direct effect on the vibrations of the machine skeleton or body. Furthermore, it is problematic, because the known damper solution is suitable to be installed only horizontally installed on a fixed base, because otherwise the mass of the known damper solution causes an extra load to the supports and bearing housings of rollers. Furthermore, the weakness is that the known damper solution cannot be applied for a multi-nip-calender, in which the vibration frequencies are so big and quick that the known damper solution does not have time to react but the known solutions even may increase the vibration sensitivity.